This invention relates to a bulk polymerized ionic polyurethane and is more particularly concerned with improved bulk polymerized ionic polyurethanes whose soft segment polyol component comprise high levels of triols along with the conventional diols.
Bulk polymerized polyurethanes are prepared in the absence of solvents. Such polyurethanes may be polymerized by an oneshot process wherein all of the ingredients are contacted under polymerization conditions. Alternatively, such polyurethanes may be prepared by a prepolymer process, wherein the polyol and isocyanate components are reacted such that an excess of isocyanate groups are present. Thereafter the prepolymer is reacted with a chain extender to form the polymer. The bulk polyurethanes may be polymerized into a final shape or processed into another form after polymerization. The bulk polyurethanes are useful in preparing shaped articles, films and in laminates.
Bulk polyurethanes do not exhibit the toughness which is required for some uses. Further, bulk polyurethanes do not demonstrate the adhesion properties desired for certain laminate applications.
What is needed is a bulk polyurethane with improved toughness and adhesion properties.